using refraction, e.g. acoustic lenses

Full Title

Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general > Methods or devices for transmitting, conducting or directing sound (G10K11/02, G10K11/36 take precedence) > Sound-focusing or directing, e.g. scanning > using refraction, e.g. acoustic lenses